2025/04/18 by Arash Azizi, Azizi, Arash
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Theory (hep-th) #Noncommutative and Quantum Gravity Theories #Quantum Electrodynamics and Casimir Effect #Quantum and Classical Electrodynamics
paper · pdf · doi:10.48550/arxiv.2505.02840
openalex publication_date 2025/04/18 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We investigate the structure of time-ordered perturbative expansions in quantum field theory (QFT) in curved spacetime, focusing on the interaction between a scalar field and multiple Unruh-DeWitt detectors undergoing uniform acceleration. Assuming the existence of a timelike Killing vector field, which serves as a global time coordinate, we express each detector's proper time in terms of this global time and consistently implement time-ordering in the Dyson series. Using light-cone coordinates and detector worldlines, we construct all possible interaction terms for two detectors at first, second, and third orders in perturbation theory. Our formalism enables a systematic classification of contributions to the S-matrix, resolving ordering ambiguities that arise due to differing accelerations and causal structure.